U.S. patent application number 16/975083 was filed with the patent office on 2021-03-25 for rotor structure, permanent magnet auxiliary synchronous reluctance motor, and electric vehicle.
The applicant listed for this patent is GREE ELECTRIC APPLIANCES, INC. OF ZHUHAI. Invention is credited to Bin CHEN, Yusheng HU, Suhua LU, Tong TONG, Yong XIAO.
Application Number | 20210091615 16/975083 |
Document ID | / |
Family ID | 1000005301185 |
Filed Date | 2021-03-25 |
United States Patent
Application |
20210091615 |
Kind Code |
A1 |
HU; Yusheng ; et
al. |
March 25, 2021 |
ROTOR STRUCTURE, PERMANENT MAGNET AUXILIARY SYNCHRONOUS RELUCTANCE
MOTOR, AND ELECTRIC VEHICLE
Abstract
A rotor structure, a permanent magnet auxiliary synchronous
reluctance motor and an electric vehicle. The rotor structure
includes a rotor body. The rotor body is provided with an outer
magnetic steel slot; an inner magnetic steel slot; a first bent
slot, a first end of the first bent slot being in communication
with the outer magnetic steel slot, and a second end of the first
bent slot extending towards an outer edge of the rotor body and
spreading gradually away from a direct axis of the rotor body; and
a third bent slot, a first end of the third bent slot being in
communication with the inner magnetic steel slot and being arranged
to be adjacent to the first bent slot, and a second end of the
third bent slot extending towards the outer edge of the rotor body
and spreading gradually away from a straight axis.
Inventors: |
HU; Yusheng; (Zhuhai,
CN) ; TONG; Tong; (Zhuhai, CN) ; LU;
Suhua; (Zhuhai, CN) ; XIAO; Yong; (Zhuhai,
CN) ; CHEN; Bin; (Zhuhai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GREE ELECTRIC APPLIANCES, INC. OF ZHUHAI |
Qianshan Zhuhai City, Guangdong |
|
CN |
|
|
Family ID: |
1000005301185 |
Appl. No.: |
16/975083 |
Filed: |
December 7, 2018 |
PCT Filed: |
December 7, 2018 |
PCT NO: |
PCT/CN2018/119793 |
371 Date: |
August 21, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60K 1/00 20130101; H02K
2213/03 20130101; H02K 1/276 20130101 |
International
Class: |
H02K 1/27 20060101
H02K001/27; B60K 1/00 20060101 B60K001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2018 |
CN |
201810218942.5 |
Claims
1. A rotor structure, comprising a rotor body provided with
magnetic steel slot groups, wherein the magnetic steel slot groups
each comprises: an outer layer magnetic steel slot; an inner layer
magnetic steel slot, wherein the outer layer magnetic steel slot
and the inner layer magnetic steel slot are arranged to be adjacent
to each other, and a magnetic conduction path is formed between the
outer layer magnetic steel slot and the inner layer magnetic steel
slot; a first bent slot, wherein a first end of the first bent slot
is in communication with the outer layer magnetic steel slot, and a
second end of the first bent slot extends towards an outer edge of
the rotor body and spreads gradually away from a direct axis; a
third bent slot, wherein, a first end of the third bent slot is in
communication with the inner layer magnetic steel slot; the third
bent slot is arranged to be adjacent to the first bent slot; and a
second end of the third bent slot extends towards the outer edge of
the rotor body and spreads gradually away from the direct axis.
2. The rotor structure of claim 1, wherein Wr1 denotes a minimum
distance between the second end of the first bent slot and the
second end of the third bent slot, and Wr2 denotes a minimum
distance between the first end of the third bent slot and a side
wall of the first bent slot, wherein Wr2/Wr1>0.8.
3. The rotor structure of claim 1, wherein the outer layer magnetic
steel slot comprises: a first outer layer magnetic steel slot
segment, wherein, a first end of the first outer layer magnetic
steel slot segment extends towards a rotation shaft hole of the
rotor body; a second end of the first outer layer magnetic steel
slot segment extends towards the outer edge of the rotor body and
spreads gradually away from the direct axis; the first bent slot is
in communication with the second end of the first outer layer
magnetic steel slot segment; and a first flux barrier is formed
between the second end of the first bent slot and the outer edge of
the rotor body; and a second outer layer magnetic steel slot
segment, wherein, a first end of the second outer layer magnetic
steel slot segment extends towards the rotation shaft hole; a
second end of the second outer layer magnetic steel slot segment
extends towards the outer and spreads gradually away from the
direct axis; the first outer layer magnetic steel slot segment and
the second outer layer magnetic steel slot segment are arranged
symmetrically relative to the direct axis; and a second flux
barrier is formed between the second end of the third bent slot and
the outer edge of the rotor body.
4. The rotor structure of claim 3, wherein the magnetic steel slot
groups each further comprises a second bent slot, wherein a first
end of the second bent slot is in communication with the second end
of the second outer layer magnetic steel slot segment; the second
end of the second bent slot extends towards the outer edge of the
rotor body and spreads gradually away from the direct axis; an
angle is formed by a length directional geometric center line of
the first bent slot, and a length directional geometric center line
of the second bent slot; and the first bent slot and the second
bent slot are arranged symmetrically relative to the direct
axis.
5. The rotor structure of claim 4, wherein A1 denotes a central
angle corresponding to an arc of a connection line between a point,
at which an extension line of a side wall of the first bent slot
proximate to the direct axis and the outer edge of the rotor body
intersect, and a point, at which an extension line of a side wall
second bent slot proximate to the direct axis and the outer edge of
the rotor body intersect, and A1>0.63.times.360.degree./p,
wherein p denotes a number of poles.
6. The rotor structure of claim 4, wherein A3 denotes a central
angle corresponding to an arc of the first flux barrier, and A2
denotes a central angle corresponding to an arc of the second flux
barrier, wherein
0.18.times.360.degree./p>A2+A3>0.13.times.360.degree./p, and
p denotes a number of poles.
7. The rotor structure of claim 1, wherein the inner layer magnetic
steel slot comprises a first inner layer magnetic steel slot
segment, a second inner layer magnetic steel slot segment, and a
third inner layer magnetic steel slot segment, which are arranged
sequentially; the first inner layer magnetic steel slot segment,
the second inner layer magnetic steel slot segment, and the third
inner layer magnetic steel slot segment are in communication with
one another sequentially to form a U-shaped structure having an
opening towards the outer edge of the rotor body.
8. The rotor structure of claim 7, wherein the rotor structure
further comprises an inner layer magnetic steel, and the inner
layer magnetic steel, comprises: a first magnetic steel disposed in
the first inner layer magnetic steel slot segment; a second
magnetic steel disposed in the second inner layer magnetic steel
slot segment; and a third magnetic steel disposed in the third
inner layer magnetic steel slot segment, wherein L1 is a length of
the first magnetic steel and a length of the third magnetic steel,
and L2 is a length of a connection line of two side walls of two
ends of the second magnetic steel towards the outer edge of the
rotor body, wherein L2/L1>0.7.
9. The rotor structure of claim 8, wherein the first magnetic
steel, the second magnetic steel, and the third magnetic steel are
spaced apart from one another; the second magnetic steel is a
plate-shaped magnetic steel; or the first magnetic steel, the
second magnetic steel, and the third magnetic steel are provided as
an integral whole, and the second magnetic steel is a U-shaped
magnetic steel.
10. A permanent magnet auxiliary synchronous reluctance motor,
comprising the rotor structure of claim 1.
11. The permanent magnet auxiliary synchronous reluctance motor of
claim 10, further comprising a stator, wherein, an inner
circumferential surface of the stator is provided with stator
teeth; the rotor body is disposed inside the stator and is
rotatable relative to the stator; an inner diameter of the stator
is Di1; an outer diameter of the rotor body is Di2, wherein
0.6<Di2/Di1<0.8.
12. The permanent magnet auxiliary synchronous reluctance motor of
claim 11, wherein closed magnetic induction lines are formed
between the rotor body and the stator; S1 denotes a length of a
magnetic induction line formed in the stator, and S2 denotes a
length of a magnetic induction line formed in the magnetic
conduction path of the rotor body), wherein
1.1S1<S2<1.3S1.
13. An electric vehicle, comprising the rotor structure of claim
1.
14. The rotor structure of claim 2, wherein the outer layer
magnetic steel slot comprises: a first outer layer magnetic steel
slot segment, wherein, a first end of the first outer layer
magnetic steel slot segment extends towards a rotation shaft hole
of the rotor body; a second end of the first outer layer magnetic
steel slot segment extends towards the outer edge of the rotor body
and spreads gradually away from the direct axis; the first bent
slot is in communication with the second end of the first outer
layer magnetic steel slot segment; and a first flux barrier is
formed between the second end of the first bent slot and the outer
edge of the rotor body; and a second outer layer magnetic steel
slot segment, wherein, a first end of the second outer layer
magnetic steel slot segment extends towards the rotation shaft
hole; a second end of the second outer layer magnetic steel slot
segment extends towards the outer edge of the rotor body and
spreads gradually away from the direct axis; the first outer layer
magnetic steel slot segment and the second outer layer magnetic
steel slot segment are arranged symmetrically relative to the
direct axis; and a second flux barrier is formed between the second
end of the third bent slot and the outer edge of the rotor
body.
15. The rotor structure of claim 2, wherein the inner layer
magnetic steel slot comprises a first inner layer magnetic steel
slot segment, a second inner layer magnetic steel slot segment, and
a third inner layer magnetic steel slot segment, which are arranged
sequentially; the first inner layer magnetic steel slot segment,
the second inner layer magnetic steel slot segment, and the third
inner layer magnetic steel slot segment are in communication with
one another sequentially to form a U-shaped structure having an
opening towards the outer edge of the rotor body.
16. The rotor structure of claim 7, wherein the rotor structure
further comprises an inner layer magnetic steel, and the inner
layer magnetic steel comprises: a first magnetic steel disposed in
the first inner layer magnetic steel slot segment; a second
magnetic steel disposed in the second inner layer magnetic steel
slot segment; and a third magnetic steel disposed in the third
inner layer magnetic steel slot segment, wherein L1 is a length of
the first magnetic steel or a length of the third magnetic steel,
and L2 is a length of a connection line of two side walls of two
ends of the second magnetic steel towards the outer edge of the
rotor body, wherein L2/L1>0.7.
17. The permanent magnet auxiliary synchronous reluctance motor of
claim 10, wherein Wr1 denotes a minimum distance between the second
end of the first bent slot and the second end of the third bent
slot, and Wr2 denotes a minimum distance between the first end of
the third bent slot and a side wall of the first bent slot, wherein
Wr2/Wr1>0.8.
18. The permanent magnet auxiliary synchronous reluctance motor of
claim 10, wherein the outer layer magnetic steel slot comprises: a
first outer layer magnetic steel slot segment, wherein, a first end
of the first outer layer magnetic steel slot segment extends
towards a rotation shaft hole of the rotor body; a second end of
the first outer layer magnetic steel slot segment extends towards
the outer edge of the rotor body and spreads gradually away from
the direct axis; the first bent slot is in communication with the
second end of the first outer layer magnetic steel slot segment;
and a first flux barrier is formed between the second end of the
first bent slot and the outer edge of the rotor body; and a second
outer layer magnetic steel slot segment, wherein, a first end of
the second outer layer magnetic steel slot segment extends towards
the rotation shaft hole; a second end of the second outer layer
magnetic steel slot segment extends towards the outer edge of the
rotor body and spreads gradually away from the direct axis; the
first outer layer magnetic steel slot segment and the second outer
layer magnetic steel slot segment are arranged symmetrically
relative to the direct axis; and a second flux barrier is formed
between the second end of the third bent slot and the outer edge of
the rotor body.
19. The permanent magnet auxiliary synchronous reluctance motor of
claim 11, wherein 0.68<Di2/Di1<0.75.
20. The permanent magnet auxiliary synchronous reluctance motor of
claim 11, wherein 0.68<Di2/Di1<0.8.
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of
motor equipment, and particularly to a rotor structure, a permanent
magnet auxiliary synchronous reluctance motor, and an electric
vehicle.
BACKGROUND
[0002] At present, new energy vehicles generally adopt rare earth
permanent magnet motors. A rare earth permanent magnet motor has a
higher power factor, and the volume of a corresponding controller
can be smaller. However, it has the disadvantages of consuming a
large amount of rare earth resources and higher cost. Therefore,
the permanent magnet reluctance motor adopting ferrite as the
permanent magnet material is gradually becoming a hot research
spot. At present, in practice the permanent magnet reluctance
motors are mostly applied in small products such as home appliances
in the industry, and have the characteristic that the torque
density is moderate, or not high, and that saturation of a magnetic
circuit is not serious. However, when the permanent magnet
reluctance motor is applied in a new energy vehicle, it is required
to have a more compact structure, and in term of design, have a
torque density twice more than that of a common permanent magnet
motor. Therefore, saturation is also quite serious, thus causing
the problem that the power factor is tremendously reduced, and
especially in the application of permanent magnet reluctance
motors, causing the reduction of efficiency of the motor.
[0003] In the prior art, a higher salient-pole ratio is obtained by
adopting a suitable ratio of inner to outer diameters, thereby
improving the efficiency of the motor. The increase of the
salient-pole ratio has a certain effect on the improvement of a
power factor. However, in the case of the saturation of the
magnetic circuit, the q-axis inductance drops rapidly, thus the
initially designed high salient-pole ratio also drops rapidly, and
the initial design becomes invalid in the case of the high
saturation of the magnetic circuit.
[0004] In the prior art, a ratio of a bottom diameter of a magnetic
steel to an outer diameter of a rotor is also set to limit a volume
percentage of the magnetic steel in the rotor, thereby ensuring a
maximum utilization of the reluctance torque. However, in a
practical research, it was found that it is not always better as
the bottom of the rotor is closer to the rotation shaft hole. Since
the closer the bottom of the rotor is to the axis, the longer the
magnetic circuit. When the magnetic circuit is highly saturated,
the inductance will attenuate more rapidly, which is prejudicial to
the improvement of the power factor.
SUMMARY OF THE INVENTION
[0005] The main objective of the present application is to provide
a rotor structure, a permanent magnet auxiliary synchronous
reluctance motor, and an electric vehicle, to solve the problem of
low efficiency of the motor in the art.
[0006] In order to achieve the above objective, according to an
aspect of the present application, a rotor structure is provided.
The rotor structure includes a rotor body provided with magnetic
steel slot groups, the magnetic steel slot groups each includes: an
outer layer magnetic steel slot; an inner layer magnetic steel
slot, wherein the outer layer magnetic steel slot and the inner
layer magnetic steel slot are arranged to be adjacent to each
other, and a magnetic conduction path is formed between the outer
layer magnetic steel slot and the inner layer magnetic steel slot;
a first bent slot, wherein a first end of the first bent slot is in
communication with the outer layer magnetic steel slot, and a
second end of the first bent slot extends towards an outer edge of
the rotor body and spreads gradually away from a direct axis; a
third bent slot, wherein, a first end of the third bent slot is in
communication with the inner layer magnetic steel slot; the third
bent slot is arranged to be adjacent to the first bent slot; and a
second end of the third bent slot extends towards the outer edge of
the rotor body and spreads gradually away from the direct axis.
[0007] Further, Wr1 denotes a minimum distance between the second
end of the first bent slot and the second end of the third bent
slot, and Wr2 denotes a minimum distance between the first end of
the third bent slot and a side wall of the first bent slot, wherein
Wr2/Wr1>0.8.
[0008] Further the outer layer magnetic steel slot includes: a
first outer layer magnetic steel slot segment, a first end of the
first outer layer magnetic steel slot segment extends towards a
rotation shaft hole of the rotor body; a second end of the first
outer layer magnetic steel slot segment extends towards the outer
edge of the rotor body and spreads gradually away from the direct
axis; the first bent slot is in communication with the second end
of the first outer layer magnetic steel slot segment; and a first
flux barrier is formed between the second end of the first bent
slot and the outer edge of the rotor body; and a second outer layer
magnetic steel slot segment, wherein, a first end of the second
outer layer magnetic steel slot segment extends towards the
rotation shaft hole; a second end of the second outer layer
magnetic steel slot segment extends towards the outer edge of the
rotor body and spreads gradually away from the direct axis; the
first outer layer magnetic steel slot segment and the second outer
layer magnetic steel slot segment are arranged symmetrically
relative to the direct axis; the first end of the third bent slot
is in communication with the second end of the second outer layer
magnetic steel slot segment, and a second flux barrier is formed
between the second end of the third bent slot and the outer edge of
the rotor body.
[0009] Further, the magnetic steel slot groups each further
includes a second bent slot, a first end of the second bent slot is
in communication with the second end of the second outer layer
magnetic steel slot segment; the second end of the first bent slot
extends towards the outer edge of the rotor body and spreads
gradually away from the direct axis; an angle is formed by a length
directional geometric center line of the first bent slot, and a
length directional geometric center line of the second bent; and
the first bent slot and the second bent slot are arranged
symmetrically relative to the direct axis.
[0010] Further, A1 denotes a central angle corresponding to an arc
of a connection line between a point, at which an extension line of
a side wall of the first bent slot proximate to the direct axis and
the outer edge of the rotor body intersect, and a point, at which
an extension line of a side wall second bent slot proximate to the
direct axis and the outer edge of the rotor body intersect, and
A1>0.63.times.360.degree./p, wherein p denotes a number of
poles.
[0011] Further, A3 denotes a central angle corresponding to an arc
of the first flux barrier, and A2 denotes a central angle
corresponding to an arc of the second flux barrier, wherein
0.18.times.360.degree./p>A2+A3>0.13.times.360.degree./p, and
p denotes a number of poles.
[0012] Further, the inner layer magnetic steel slot comprises a
first inner layer magnetic steel slot segment, a second inner layer
magnetic steel slot segment, and a third inner layer magnetic steel
slot segment, which are arranged sequentially; the first inner
layer magnetic steel slot segment, the second inner layer magnetic
steel slot segment, and the third inner layer magnetic steel slot
segment are in communication with one another sequentially to form
a U-shaped structure having an opening towards the outer edge of
the rotor body.
[0013] Further, the rotor structure further comprises an inner
layer magnetic steel, and the inner layer magnetic steel includes:
a first magnetic steel disposed in the first inner layer magnetic
steel slot segment; a second magnetic steel disposed in the second
inner layer magnetic steel slot segment; and a third magnetic steel
disposed in the third inner layer magnetic steel slot segment, L1
is a length of the first magnetic steel and/or a length of the
third magnetic steel, and L2 is a length of a connection line of
two side walls of two ends of the second magnetic steel towards the
outer edge of the rotor body, wherein L2/L1>0.7.
[0014] Further, the first magnetic steel, the second magnetic
steel, and the third magnetic steel are spaced apart from one
another; the second magnetic steel is a plate-shaped magnetic
steel; or the first magnetic steel, the second magnetic steel, and
the third magnetic steel are provided as an integral whole, and the
second magnetic steel is a U-shaped magnetic steel.
[0015] According to another aspect of the present application, a
permanent magnet auxiliary synchronous reluctance motor is
provided, and the permanent magnet auxiliary synchronous reluctance
motor includes any one of the rotor structures above.
[0016] Further, the permanent magnet auxiliary synchronous
reluctance motor includes a stator, an inner circumferential
surface of the stator is provided with stator teeth; the rotor body
is disposed inside the stator and is rotatable relative to the
stator; an inner diameter of the stator is Di1; an outer diameter
of the rotor body is Di2, wherein 0.6<Di2/Di1<0.8.
[0017] Further, closed magnetic induction lines are formed between
the rotor body and the stator; S1 denotes a length of a magnetic
induction line formed in the stator, and S2 denotes a length of a
magnetic induction line formed in the magnetic conduction path of
the rotor body, wherein 1.1S1<S2<1.351.
[0018] According to another aspect of the present application, an
electric vehicle is provided, and the electric vehicle includes any
one of the rotor structures above.
[0019] By applying the technical solutions of the present
application, the first bent slot and the second bent slot are
respectively arranged to be in communication with the outer layer
magnetic steel slot and the inner layer magnetic steel slot, and
the first bent slot and the second bent slot are arranged to extend
outwards in a radial direction of the rotor body and spread
gradually away from the direct axis of the magnetic steel slot
group. Such an arrangement effectively increases the distance of
the magnetic conduction path between the first bent slot and the
second bent slot, thereby improving the performance of the rotor
body and the efficiency of the motor having the rotor
structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which constitute a part of this
application, are used to provide further understanding of the
present application. The illustrative embodiments of the present
application and the descriptions thereof are used to interpret the
present application, but not intended to constitute any improper
limitation on the present application. In the drawings:
[0021] FIG. 1 is a schematic structure diagram illustrating a rotor
structure according to a first embodiment of the present
application;
[0022] FIG. 2 is a schematic structure diagram illustrating a rotor
structure according to a second embodiment of the present
application;
[0023] FIG. 3 is a schematic structure diagram illustrating a rotor
structure according to a third embodiment of the present
application;
[0024] FIG. 4 is a schematic structure diagram illustrating a rotor
structure according to a fourth embodiment of the present
application.
[0025] The above-mentioned figures include the following reference
signs:
[0026] 10, rotor body; 13, rotation shaft hole;
[0027] 11, outer layer magnetic steel slot; 111, first outer layer
magnetic steel slot segment; 112, second outer layer magnetic steel
slot segment; 113, first bent slot; 114, second bent slot;
[0028] 12, inner layer magnetic steel slot; 121, first inner layer
magnetic steel slot segment; 122, second inner layer magnetic steel
slot segment; 123, third inner layer magnetic steel slot segment;
124, third bent slot; 125, fourth bent slot;
[0029] 20, outer layer magnetic steel;
[0030] 30, inner layer magnetic steel; 31, first magnetic steel;
32, second magnetic steel; 33, third magnetic steel;
[0031] 40, stator; 41, stator tooth;
[0032] 51, first flux barrier; 52, second flux barrier.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0033] It should be noted that, under the premise of no conflict,
the embodiments in the present application and the features
included in the embodiments can be combined with each other. The
present application will be described in detail below with
reference to the drawings combining with the embodiments.
[0034] It should be noted that, the terminology herein is used for
describing the specific embodiments, but not intended to limit the
illustrative embodiments of the present application. The singular
terms herein are intended to include their plural unless specific
descriptions are provided in context. Additionally, it should be
also understood that, the terms "include" and/or "comprise" in the
description refer to including the features, steps, operations,
devices, components, and/or combinations thereof.
[0035] It should be specified that the terms "first", "second",
etc. in the description, the claims and the drawings in the present
application are just used to distinguish similar objects, but not
used to describe a specific order or an order of priority. It
should be understood that such terms may be interchangeable under
appropriate conditions, such that the embodiments of the present
application illustrated in the drawing or described herein can be
implemented, for example, in a sequence other than the sequences
illustrated or described herein. In addition, the terms "comprise",
"have" and any variations thereof are intended to cover a
non-exclusive inclusion. For example, a process, a method, a
system, a product, or a device that includes a series of steps or
units is not limited to those steps or units listed clearly, but
may include other steps or units, which are not clearly listed, or
which are inherent to such a process, a method, a product or a
device.
[0036] For the convenience of description, terms of spatial
relations such as "above", "over", "on a top surface", "upper",
etc., may be used herein to describe the spatial position
relationships of a device or a feature with other devices or
features shown in the drawings. It should be understood that the
terms of spatial relations are intended to include other different
orientations in use or operation in addition to the orientation of
the device described in the drawings. For example, if the device in
the drawings is placed upside down, the device described as "above
other devices or structures" or "over other devices or structures"
will be positioned as "below other devices or structures" or "under
other devices or structures". Thus, the exemplary term "above" may
include both "above" and "below". The device can also be positioned
in other different ways (rotating 90 degrees or at other
orientations), and the corresponding explanations for the
description of the spatial relations will be provided herein.
[0037] The exemplary embodiments according to the present
application will be described in more detail in reference to the
drawings herein. However, these exemplary embodiments can be
implemented in various manners, and they should not be construed as
limitation to the embodiments illustrated herein only. It should be
understood that the provision of these embodiments is to make the
disclosure of the present application more sufficient and thorough,
and to sufficiently convey the concept of the exemplary embodiments
to those skilled in the art. For the clarity, thicknesses of layers
and regions may be increased, and the same devices are denoted by
the same reference sign, thereby omitting the description
thereof.
[0038] Referring to FIGS. 1 to 4, a rotor structure is provided
according to embodiments of the present application.
[0039] As shown in FIG. 1, the rotor structure includes a rotor
body 10. The rotor body 10 is provided with magnetic steel slot
groups. The magnetic steel slot groups each include an outer layer
magnetic steel slot 11, an inner layer magnetic steel slot 12, a
first bent slot 113, and a third bent slot 124. The outer layer
magnetic steel slot 11 and the inner layer magnetic steel slot 12
are arranged to be adjacent to each other. A magnetic conduction
path is formed between the outer layer magnetic steel slot 11 and
the inner layer magnetic steel slot 12. A first end of the first
bent slot 113 is in communication with the outer layer magnetic
steel slot 11. A second end of the first bent slot 113 extends
towards an outer edge of the rotor body 10 and spreads gradually
away from a direct axis, that is, the d-axis (shown in FIG. 4), of
the rotor body 10. A first end of the third bent slot 124 is in
communication with the inner layer magnetic steel slot 12 and is
adjacent to the first bent slot 113. A second end of the third bent
slot 124 extends towards the outer edge of the rotor body 10 and
spreads gradually away from the direct axis.
[0040] In this embodiment, the outer layer magnetic steel slot and
the inner layer magnetic steel slot are respectively provided with
the first bent slot and the second bent slot, which are
respectively in communication with the outer layer magnetic steel
slot and the inner layer magnetic steel slot, and the first bent
slot and the second bent slot are arranged to extend outwards in a
radial direction of the rotor body and spread gradually away from
the direct axis of the magnetic steel slot group. Such an
arrangement effectively increases the distance of the magnetic
conduction path between the first bent slot and the second bent
slot, thereby improving the performance of the rotor body and the
efficiency of a permanent magnet auxiliary synchronous reluctance
motor (hereinafter referred as to motor) having the rotor
structure.
[0041] Specifically, Wr1 denotes a minimum distance between the
second end of the first bent slot 113 and the second end of the
third bent slot 124, and Wr2 denotes a minimum distance between the
first end of the third bent slot 124 and a side wall of the first
bent slot 113, where Wr2/Wr1>0.8. Such an arrangement can
effectively mitigate the saturation at an inlet of the magnetic
conduction path.
[0042] The outer layer magnetic steel slot 11 includes a first
outer layer magnetic steel slot segment 111 and a second outer
layer magnetic steel slot segment 112. A first end of the first
outer layer magnetic steel slot segment 111 extends towards a
rotation shaft hole 13 of the rotor body 10. A second end of the
first outer layer magnetic steel slot segment 111 extends towards
the outer edge of the rotor body 10 and spreads gradually away from
the direct axis. The first bent slot 113 is in communication with
the second end of the first outer layer magnetic steel slot segment
111. A first flux barrier 51 is formed between the second end of
the first bent slot 113 and the outer edge of the rotor body 10. A
first end of the second outer layer magnetic steel slot segment 112
extends towards the rotation shaft hole 13. A second end of the
second outer layer magnetic steel slot segment 112 extends towards
the outer edge of the rotor body 10 and spreads gradually away from
the direct axis. The first outer magnetic steel slot segment 111
and the second outer magnetic steel slot segment 112 are arranged
symmetrically relative to the direct axis. The first end of the
third bent slot 124 is in communication with the second end of the
second outer layer magnetic steel slot segment 112. A second flux
barrier 52 is formed between the second end of the third bent slot
124 and the outer edge of the rotor body 10.
[0043] The magnetic steel slot group further includes a second bent
slot 114. A first end of the second bent slot 114 is in
communication with the second end of the second outer layer
magnetic steel slot segment 112. The second end of the first bent
slot 113 extends towards the outer edge of the rotor body 10 and
spreads gradually away from the direct axis. An angle is formed by
a length directional geometric center line of the first bent slot
113 and an extension line of a length directional geometric center
line of the second bent slot 114. The first bent slot 113 and the
second bent slot 114 are arranged symmetrically relative to the
direct axis. Such an arrangement can effectively improve the
magnetic conduction performance of the rotor structure.
[0044] As shown in FIG. 3, A1 denotes a central angle corresponding
to an arc of a connection line between a point, at which an
extension line of a side wall of the first bent slot 113 proximate
to the direct axis and the outer edge of the rotor body 10
intersect, and a point, at which an extension line of a side wall
of the second bent slot 114 proximate to the direct axis and the
outer edge of the rotor body 10 intersect, and
A1>0.63.times.360.degree./p, where p denotes a number of poles.
A3 denotes a central angle corresponding to an arc of the first
flux barrier 51, and A2 denotes a central angle corresponding to an
arc of the second flux barrier 52, where
0.18.times.360.degree./p>A2+A3>0.13.times.360.degree./p, and
p denotes the number of poles. Such an arrangement can ensure the
salient pole ratio not to decrease while increasing an area of a
magnetic conduction portion at an outer periphery of the rotor,
thereby increasing flux linkage of permanent magnets.
[0045] As shown in FIG. 4, the inner layer magnetic steel slot 12
includes a first inner layer magnetic steel slot segment 121, a
second inner layer magnetic steel slot segment 122, and a third
inner layer magnetic steel slot segment 123, which are arranged
sequentially. The first inner layer magnetic steel slot segment
121, the second inner layer magnetic steel slot segment 122, and
the third inner layer magnetic steel slot segment 123 are in
communication with one another sequentially to form a U-shaped
structure having an opening towards the outer edge of the rotor
body 10.
[0046] As shown in FIG. 1, the rotor structure further includes an
inner layer magnetic steel 30. The inner layer magnetic steel 30
includes a first magnetic steel 31, a second magnetic steel 32, and
a third magnetic steel 33. The first magnetic steel 31 is disposed
in the first inner layer magnetic steel slot segment 121. The
second magnetic steel 32 is disposed in the second inner layer
magnetic steel slot segment 122. The third magnetic steel 33 is
disposed in the third inner layer magnetic steel slot segment 123.
L1 is a length of the first magnetic steel 31 and/or a length of
the third magnetic steel 33, and L2 is a length of a connection
line between two side walls of two ends of the second magnetic
steel 32 towards the outer edge of the rotor body 10, where
L2/L1>0.7. Such an arrangement can ensure the better utilization
of the permanent magnet namely the magnetic steel, thereby
preventing the U-shaped structure from being excessively concave. A
bottom of the U-shaped structure can be a straight segment or a
curved segment.
[0047] As shown in FIGS. 1 and 2, the first magnetic steel 31, the
second magnetic steel 32, and the third magnetic steel 33 are
spaced apart from one another, and the second magnetic steel 32 is
a plate-shaped magnetic steel. As shown in FIG. 4, the first
magnetic steel 31, the second magnetic steel 32, and the third
magnetic steel 33 are provided as an integral whole, and the second
magnetic steel 32 is a U-shaped magnetic steel.
[0048] The rotor structures of the above embodiments can also be
applied in the technical field of motor equipment. That is,
according to another aspect of the present application, a motor is
provided. The motor includes a rotor structure, and the rotor
structure is any one of the above-mentioned rotor structures.
[0049] The rotor structures of the above embodiments can also be
applied in the technical field of vehicles. That is, according to
another aspect of the present application, an electric vehicle is
provided. The electric vehicle includes a rotor structure, and the
rotor structure is any one of the above-mentioned rotor
structures.
[0050] In an embodiment, the outer layer magnetic steel slot and
the inner layer magnetic steel slot are respectively provided with
the first bent slot and the second bent slot, which are
respectively in communication with the outer layer magnetic steel
slot and the inner layer magnetic steel slot, and the first bent
slot and the second bent slot are arranged to gradually spread away
from the direct axis of the flux slot group outwards and in a
radial direction of the rotor body. Such an arrangement effectively
increases a magnetic conduction distance between the first bent
slot and the second bent slot, thereby improving the performance of
the rotor body and the efficiency of the motor having the rotor
structure.
[0051] Referring to FIGS. 1 and 2, the motor further includes a
stator 40. An inner circumferential surface of the stator 40 is
provided with stator teeth 41. The rotor body 10 is disposed inside
the stator and is rotatable relative to the stator 40. An inner
diameter of the stator 40 is Di1, and an outer diameter of the
rotor body 10 is Di2, where 0.6<Di2/Di1<0.8. D1 is an outer
diameter of the stator. Such an arrangement can effectively improve
the resistance to the saturation of the motor, thereby effectively
increasing the power of the motor and decreasing the costs of
manufacturing the motor. Of course, preferably, a value of Di2/Di1
is from 0.68 to 0.75.
[0052] As shown in FIG. 1, closed magnetic induction lines are
formed between the rotor body 10 and the stator 40. S1 denotes a
length of the magnetic induction line formed in the stator 40, and
S2 denotes a length of the magnetic induction line formed in the
magnetic conduction path of the rotor body 10, where
1.1S1<S2<1.3S1. Such an arrangement can effectively avoid a
decrease of the power factor caused by the excessively concave
rotor in a case that the motor is heavily loaded.
[0053] Specifically, the rotor body is disposed rotatably inside
the stator by means of the rotation shaft hole, and there is an air
gap between the stator and the rotor. The rotor has a plurality of
poles, each of which has a magnetic steel slot group. The magnetic
steel slot group includes a plurality of magnetic steel slots. The
plurality of magnetic steel slots are arranged in a radial
direction. The magnetic steel slot is a hollow air slot, and
penetrates in an axial direction of an iron core. The magnetic
steel is arranged in a corresponding magnetic steel slot. After the
rotor is assembled, portions of the magnetic steel slots, which are
proximate to the outer periphery of the rotor, are not fully filled
and form the bent slots at ends of the magnetic steel slots. The
flux barrier having a thin-wall structure are disposed between the
bent slots and the air gap, thus having effects of structurally
connecting punching sheets of the rotor as a whole, preventing the
magnetic circuit passing through the flux barrier by means of
magnetic saturation of the thin-wall structure, and realizing
magnetic isolation.
[0054] The increase of the outer diameter of the rotor of the motor
can make the total length of the air gap increase, that is, the
peripheral area of the rotor increases, thereby making the value of
the flux linkage increase. Moreover, a width of the magnetic
conduction path between two magnetic steels can also increase,
which facilitates the increase of the torque. However, the decrease
of the stator area may also result in increase of the resistance of
the stator. Through a research, it was found that, as for a
permanent magnet reluctance motor applied in a new energy vehicle,
the increase of the outer diameter Di2 of the rotor facilitates an
anti-saturation design, thereby improving the power factor when the
motor is heavily loaded. Preferably, when 0.68<Di2/Di1<0.8,
the effect of resistance to the saturation of the magnetic circuit
are better when the motor is heavily loaded.
[0055] Of course, the increase of the outer diameter makes the
amount of magnetic steel increase, and makes the amount of cooper
decrease. Taking account of costs, if 0.6<Di2/Di1<0.75 is
satisfied, an advantage of preferable costs can be achieved. When
the inner diameter is too small, a proportion of the costs of the
required cooper amount is high, and when the outer diameter
increases, the required cooper amount decreases significantly,
thereby decreasing the costs. When the inner diameter is too large,
the effect of further decreasing the cooper amount is not improved
remarkably due to the constant dimension of end portions of
windings, while the required amount of magnetic steel increases in
direct proportion to the outer diameter, thus increasing the
costs.
[0056] When the motor is heavily loaded, the decrease of the power
factor is substantially caused by the saturation of the magnetic
circuit. The design space available for the volume of the magnetic
conduction path is small due to the limitation of the structure of
the reluctance motor, which is the main reason for the saturation
of the magnetic circuit. Regarding this problem combining with the
distribution of the magnetic induction lines, the design of the
magnetic conduction path between the end portions of the two
magnetic steel slots has following features: the distance Wr1
proximate to the outer periphery of the rotor and the minimum
distance Wr2 of the magnetic conduction path at a bent points of
the magnetic steels satisfy following relationship: Wr2/Wr1>0.8,
where Wr1 denotes a width of a main path through which the rotor
receives the stator magnetic induction lines from the stator. When
the magnetic conduction path further spreads towards the rotation
shaft hole 13, under the influence of the magnetic field, a
magnetic field at the inner portion of the magnetic conduction path
is much smaller than a magnetic field at a portion of the magnetic
conduction path, which is adjacent to the end portions of the
magnetic steel slots. As the end portions of the magnetic steel
slots are arranged to spread outwards, Wr1>Wr2 is always
satisfied. If the end portions of the magnetic steel slots spread
outward too much, then Wr2/Wr1 is too small. Thus, the saturation
of the magnetic circuit of the portion can reach 3T or more. The
torque constant decreases, and the power factor also decreases
rapidly.
[0057] The design of concavity of the rotor can make the amount of
inner layer arm magnetic steel permanent magnets increase, thereby
increasing the flux linkage of permanent magnets, and improving the
power factor. However, with a further increase of concave degree of
the concavity, two following problems will occur: 1. a volume of an
inner layer bottom magnetic steel is reduced; 2. the magnetic
conduction path of the rotor is lengthened while magnetic potential
consumption in the rotor increase, and moreover, an increase of a
portion of the rotor conducting magnetic flux will result in the
increase of iron losses. Thus, continuing increasing the magnetic
steels is useless. Through a research, it was found that the
constraints of the following two conditions can make the depth of
the concavity to be reasonably controlled. When the length L1 of
the inner layer arm magnetic steel and the inner layer bottom
magnetic steel satisfy the following relationship L2/L1>0.7, the
mount of permanent magnets can be ensured to be better. Moreover,
the magnetic induction lines in the rotor should be prevented from
being too long, thereby causing unnecessary magnetic potential
consumption in the rotor, which will increase when the motor is
heavily loaded. When the length S1 of the magnetic induction line
passing through the stator and the length of the magnetic induction
line passing through the rotor satisfy the following
relationship:1.1S1<S2<1.3S1, the decrease of the power
factor, which is caused by the too deep concavity in the rotor when
the motor is heavily loaded, can be avoided, wherein the length S2
corresponds to a magnetic induction line passing through a middle
portion of the magnetic conduction path between two layers of
magnetic steels of each pole, and the length S1 corresponds to a
magnetic induction line passing through a middle portion of a tooth
corresponding to the end portion of the magnetic conduction path
and a middle portion of a rim. The increase of the permanent magnet
torque component also has effects on improvement of the power
factor. In order to increase the permanent magnet torque component,
the magnetic conduction area in the d-axial direction is increased,
and a sum of the lengths of the flux barriers at the end portions
of the magnetic steel slots is limited to be within a certain
range, thus the salient pole ratio can be ensured not to decrease
significantly, while the area of the magnetic conduction portion at
the outer periphery of the rotor is increased, thereby increasing
the flux linkage of permanent magnets. An outer layer magnetic
steel 20 is disposed in the outer layer magnetic steel slot. The
end portion of the inner layer magnetic steel slot is further
provided with a fourth bent slot 125. The fourth bent slot 125 is
arranged to be opposite to the third bent slot 124 arranged in the
same magnetic steel slot group.
[0058] When the rotor is an integral U-shaped structure, a
tangential horizontal line is drawn at the middle portion of the
intermediate magnetic conduction path dividing the U-shaped
structure into arms and a bottom. In the case, the length L2 of the
bottom magnetic steel and the length L1 of the arm magnetic steels
are illustrated in FIG. 4.
[0059] In addition to the above description, it should be noted
that "an embodiment", "another embodiment", "embodiment", and the
like, which are mentioned in the application, indicate that a
specific feature, structure or character described combining with
the embodiments is included in at least one embodiment that is
generally described in the present application. The same expression
appearing in multiple places in the specification is not intended
to have to refer to the same embodiment. Further, when a specific
feature, structure, or character is described combining with any
one of the embodiments, a claim claiming a combination of such
feature, structure, or character with other embodiments also falls
within the scope of the present application.
[0060] In the above embodiments, the description of each embodiment
has its own emphasis. A part that is not described in detail in an
embodiment can refer to the related description in other
embodiments.
[0061] What described above are merely preferred embodiments of the
present application, but are not intended to limit the present
application. For those skilled in the art, the present application
may have various modifications and changes. Any modification,
equivalent replacement, or improvement made within the spirit and
principle of the present application shall fall in the protection
scope of the present application.
* * * * *